The present disclosure relates to polymer-cellulose composites, and more particularly, the present disclosure relates to conductive polymer-cellulose nanocomposites.
Cellulose is one of the most abundant renewable biomaterials on earth. It is a linear condensation polymer of glucose units joined together by β-1,4-glycosidic bonds. Though commonly found as fibrous materials with both amorphous and crystalline regions in nature, highly crystalline nanocellulose material of both needle and spherical shapes can be prepared through acid hydrolysis methods [1-4].
Meanwhile, organic conductive polymers have been widely investigated since their introduction in the 1970's due to their good environmental stability and desirable electrical, chemical and optical properties [5, 6]. Among various types of conductive polymers, polypyrrole (PPy) and polyaniline received most attention. PPy has been shown to have promising applications in many areas, such as to be used as electrode materials in rechargeable lithium batteries, substrates for sensors, and antistatic coatings and packaging, and etc. [7-9].
More recently, efforts were made to produce more environmentally friendly conductive polymer composites and films by combining renewable cellulosic materials with a conductive polymer. With the conductive polymer encapsulating the cellulosic component, the novel hybrid materials showed combined characteristics of both components [10-15]. However, the cellulose materials still retained their original physical attributes (dimensions) and chemical properties. Meanwhile, it is well known that nano-cellulose materials are typically very difficult to re-disperse in high concentrations in water or solvents and have poor drainage properties. At low moisture concentrations, nano-cellulose materials become gels and water cannot be easily removed. In addition, cellulose-polypyrrole composites reported in the literature appear to be black and opaque solids (film or paper) that limit their potential applications. Some had poor flexibility and high brittleness [16].